Every year there is an increase in the use of drugs of abuse by the general population. Although experts have no appreciable difficulty in identifying most drugs in a well equipped laboratory, numerous situations occur where it is important to be able to detect common drugs of abuse outside the laboratory. Such situations occur frequently for law enforcement officers concerned with combatting illicit drug trade and use. Such persons need simple, rapid and specific methods for detecting drugs of abuse in the field. In addition, the methods of detection should be such that they can be performed by persons having minimum training.
Numerous reagents have been reported in the literature for detecting drugs of abuse (see for example, Arch. Toxikol., 25, 19(1969), J. Pharm. Sci., 56, 1526(1967)). Many of these reagents however are non-specific and/or give false positives when the suspected sample contains diluents and adulterants. Cobaltous thiocyanate, for example, is used as a color reagent for the detection of cocaine; however in excess of 50 other substances give a similiar color reaction with this reagent. Moreover, the testing of brown heroin with the recognized reagent for natural narcotics, i.e., the Marquis reagent (8-10 drops 40% formaldehyde/10 ml. concentrated sulfuric acid), has resulted in false positives due to the presence of dyes and pigments in the heroin samples. In addition, safety problems, such as acid spattering and the abrupt evolution of gases causing rupture of the sample container have been encountered in the field when reagents containing large amounts of strong acids were added to suspect liquid and powder samples.
Further, new smuggling techniques are constantly being developed by illegal drug traffikers which render many of the available field-test reagents useless or unreliable. Alcoholic solutions of pure cocaine, for example, cannot be meaningfully tested with either cobaltous thiocyanate or the Marquis reagent.
It would therefore be desirable to develop rapid, highly specific, non-hazardous methods for detecting the presence of drugs of abuse, which methods for detecting the presence of drugs of abuse, which methods could be easily performed in the field by persons having minimum training.